This phase I study will determine the maximum tolerated dose of 90Y-CC49 monoclonal antibody with alpha-interferon in patients with advanced non-small cell lung cancer. Other goals are: to evaluate safety and efficacy of concomitant calcium disodium EDTA administration to increase the maximum tolerated dose of 90Y-CC49, to determine biodistribution, dosimetry and tumor targeting data with 111IN-CC49 antibody, and to obtain pharmacokinetic data of 90Y-CC49. The initial dose level of 90Y-CC49 is 8mCi/m2 in an antibody dose of 10mg of CC49. Subsequent dose escalation will be on the basis of 3.0 mCi/m2 per dose level. A total of three patients have been entered at the first dose level (8mCi/m2). Two of these patients experienced grade 3 thrombocytopenia (reversible); otherwise treatment has been well tolerated. In view of this hematologic toxicity, 2 additional patients will be included in the first group o patients at dose level 1 (8mCi/m2). If significant myelosuppression is observed, then a different group of patients will be treated with EDTA infusion.